feat(bot): add support for Discord message context commands (#513)

PluralKit.Bot/ApplicationCommandMeta/ApplicationCommand.cs

@@ -0,0 +1,17 @@
+using ApplicationCommandType = Myriad.Types.ApplicationCommand.ApplicationCommandType;
+
+namespace PluralKit.Bot;
+
+public class ApplicationCommand
+{
+    public ApplicationCommand(ApplicationCommandType type, string name, string? description = null)
+    {
+        Type = type;
+        Name = name;
+        Description = description;
+    }
+
+    public ApplicationCommandType Type { get; }
+    public string Name { get; }
+    public string Description { get; }
+}